The speaker, in general, is a device to generate sound in such a way to convert an electrical energy into a physical energy, wherein the device is able to generate an acoustic or high or low sound based on a sound source.
The aforementioned speaker may be categorized based on a producing method into a moving coil type dynamic speaker, an electrostatic speaker, a ribbon speaker, and a piezoelectric speaker. As another type of a speaker, there is a coaxial speaker.
Moreover, in order to maximize a performing effect at a theater, for example, a concert theater, a line speaker system, which is a large speaker system, is mainly used, wherein a plurality of speakers are connected in series in one direction (for example, an upward and downward direction).
FIG. 1A is a cross sectional view illustrating a conventional coaxial speaker.
Referring to FIG. 1A, the coaxial speaker includes a low-pitched tone speaker 11 which corresponds to a woofer configured to reproduce a low-pitched sound, a high-pitched sound speaker 13 which corresponds to a tweeter installed at an upper portion of the low-pitched sound speaker 11 and configured to product a high-pitched sound, and a connection member 15 configured to connect the low-pitched sound speaker 11 and the high-pitched sound speaker 13 to a coaxial portion. The lower portion of the connection 15 is inserted into the low-pitched sound speaker 11, and the high-pitched sound speaker 13 is accommodated in the upper portion thereof. In this way, the low-pitched sound speaker 11 and the high-pitched sound speaker 13 can be connected to the coaxial portion.
In the aforementioned conventional coaxial speaker, since the low-pitched sound speaker 11 and the high-pitched sound speaker 13 are integrally connected to the connection member 15, the position of the high-pitched sound speaker 13 can't be adjusted. For this reason, it is impossible to product various sound qualities due to the position adjustment (an orienting angle adjustment) of the high-pitched speaker 13, thus causing a disadvantage.
According to another conventional technology which is suggested to resolve the aforementioned problems, an improved coaxial speaker has been developed, which is able to adjust the position of the high-pitched sound speaker.
More specifically, FIG. 1B is a cross sectional view illustrating the conventional technology improved coaxial speaker, and FIG. 1C is a disassembled perspective view illustrating the first and the second support members in FIG. 1B.
Referring to FIGS. 1B and 1C, the improved coaxial speaker includes a low-pitched sound speaker (a woofer) 110 configured to reproduce a low-pitched sound, and a high-pitched sound speaker 120 which positions coaxial with the low-pitched sound speaker 110 with respect to a virtual vertical line and generally positions higher than the low-pitched sound speaker 110 and is configured to reproduce a high-pitched sound. In this case, the surface facing the low-pitched sound speaker 110 with respect to a virtual vertical line is defined as a lower surface, and the surface facing high-pitched sound speaker 120 is defined at an upper surface.
The low-pitched sound speaker 110 includes the first frame 111, the first plate 113 engaged to the lower surface of the first frame 111, the first magnet 114 engaged to the lower surface of the first plate 113, the first yoke 115 engaged to the lower surface of the first magnet 114, the first vibration plate 117 a rim portion of which is engaged to the first frame 111, and the first voice coil 118 an upper portion of which is engaged to a central portion of the first vibration plate 117, and a lower portion of which positions between the first plate 113 and the first yoke 115. If an external electric power is supplied to the first voice coil 118, the first voice coil 118 will vibrate upward and downward by the operations of the first voice coil 118 and the first magnet 114, by which the first vibration plate 177 will vibrate upward and downward, thus producing a low-pitched acoustic.
Meanwhile, the high-pitched sound speaker 120 includes the second frame 121, the second yoke 123 engaged to the inner surface of the second frame 121, the second magnet 124 and the second plate 125 which are laminated in order inside of the second yoke 123 at a predetermined interval from the inner surface of the second yoke 123, the second vibration plate 127 a rim portion of which is engaged to the second frame, and the second voice coil 128 an upper portion of which is engaged to the second vibration plate 127, and a lower portion of which positions between the second yoke 123 and the second plate 125. If an external current is supplied to the second voice coil 128, the second voice coil 128 will vibrate upward and downward by the operations of the second voice coil 128 and the second magnet 124, by which the second vibration plate 127 will vibrate upward and downward, thus producing a high-pitched acoustic.
The low-pitched sound speaker 110 and the high-pitched sound speaker 120 are connected to a coaxial portion with the aid of the first support member 130 and the second support member 140. The rotation and the orienting angle of the high-pitched sound speaker 120 of the embodiment can be adjusted by the first and the second support members 130 and 140.
More specifically, a lower portion of the first support member 130 is fixed at the low-pitched sound speaker 110, and an upper portion thereof can rotate about a virtual vertical line. The first support member 130 includes a lower support member 131, an intermediate support member 134 and an upper support member 137. Moreover, the lower support member 131 is formed in a cylindrical shape, and an outer circumferential surface of the lower portion thereof is fixedly inserted into the first yoke 115. A support rim 131a protruding outward is formed at an outer circumferential surface of the central portion of the lower support member 131, and a plurality of first engaging protrusions 131b are formed in the longitudinal direction at an outer circumferential surface of the upper portion thereof.
The conventional technology coaxial speaker in FIG. 1A to FIG. 1C has the Korean patent application No. 10-2007-0080525 which was filed on Aug. 10, 2007 by Jung, Chang-gyu with the title of “a coaxial speaker”. This was registered on Jun. 3, 2009, and the contents thereof are described in detail in the Korean patent registration No. 10-0902089.
In the conventional technology coaxial speaker in FIG. 1A to FIG. 1C, it is advantageous that the low-pitched sound speakers 11 and 110 and the high-pitched sound speakers 13 and 120 can be connected coaxial, and the rotation and orienting angle of the high-pitched sound speaker 120 can be adjusted by the first and the second support members 130 and 140, but the following problems has remain occurred.
More specifically, FIG. 1D is a schematic view illustrating a propagation state of a high-pitched sound when the conventional technology coaxial speaker is used.
Referring to FIG. 1D, in the conventional technology, the low-pitched sound speakers 11 and 110 are equipped with a large horn-shaped the first vibration plate 117, while the high-pitched sound speakers 13 and 120 are equipped with a relatively smaller convex curve-shaped the second vibration plate 127. As illustrated in FIG. 1D, a high-pitched sound reproduced from the high-pitched sound speakers 13 and 120 can spread within an orienting angle range (a relatively narrower range) along the second frame 121. If the speaker in FIG. 1D is used alone, there may not be any interference phenomenon, but if a line array speaker system is used, wherein a plurality of speakers are arranged in upper and lower and leftward and rightward directions while neighboring with each other, a high-pitched sound having a relatively shorter wavelength/high frequency than a low-pitched sound may be likely to cause an interference phenomenon with another high-pitched sound which is reproduced from another speaker among a plurality of the speakers. For example, a problem occurs, wherein a high-pitched sound is not well transferred or heard weak to an audience who is at a predetermined position in a wider performing theater.
More specifically, FIG. 1E is a schematic view illustrating a propagation state of a high-pitched sound if a line speaker system is used, wherein a plurality of conventional technology coaxial speakers are connected in one direction. As illustrated in FIG. 1E, a line speaker system is illustrated, wherein three coaxial speakers are disposed in line, and it is obvious that two or four or more than four coaxial speakers can be used.
Referring to FIG. 1E, according to the conventional technology line array speaker system, a high-pitched sound reproduced from each coaxial speaker, as illustrated in FIG. 1D, will spread along the second frame 121. In this case, since the vibration plates 127 of each high-pitched sound speaker 120 are disposed spaced-apart from each other, the wave fronts (WF1, WF2, WF3) of a high-pitched tone reproduced from each vibration plate 127 may be superposed. A constructive interference (CI) may occur where a high-pitched sound wavelength does not have any path difference or corresponds to even number multiples of a half wavelength, and a destructive interference (DI) may occur where a high-pitched sound wavelength corresponds to odd number multiples of a half wavelength. If a conventional line speaker system illustrated in FIG. 1E is used in a performing theater, there may be a problem wherein a high-pitched sound may not be transferred to an audience who is at a position where a destructive interference occurs or may be heard weak.
In order to resolve the aforementioned conventional technology problems, it needs to develop a new resolution.